This is what you need.
Bed side step with no moving parts, nothing hanging down. Some might think it's ugly. I think its practicality is beautiful. Unfortunately the rest of the truck is included.

 

Those GM trucks look like chop tops to me. I think they would look a bit better if the greenhouse was a tiny bit taller. Then again, those HD trucks are tall enough already. I saw an article in Car and Driver talking about their limited visibility due to the tall height. The Sierra HD I think the leading edge of the hood was almost 6 ft off the ground. WTF? Then folks go and add 6 or 7 inch lifts. Sheesh.